The present invention relates to the treatment of slag in industrial furnaces or the like, and more particularly to improvements in apparatus for quenching and further processing of slag. Still more particularly, the invention relates to improvements in apparatus of the type wherein slag which issues from a furnace (e.g., a slag tap furnace) is fed into a liquid-containing quenching vessel and is thereupon evacuated from the vessel into a chute or duct to overflow at the discharge end of the chute.
In many presently known slag processing apparatus, quenched slag is evacuated from the vessel by a piston or pusher which advances batches of slag from the liquid bath into and along the upwardly sloping bottom of the chute. The material which overflows at the discharge end of the chute is caused to descend onto a conveyor (e.g., a belt conveyor) or directly into a vehicle. The length of the chute is limited, i.e., such length cannot be increased at will, because of the damming effect of wet material which is advanced from the liquid bath toward the discharge end and also because the bottom of the chute slopes upwardly in order to insure that a substantial percentage of liquid which is entrained from the bath returns into the vessel by flowing counter to the direction of movement of slag. In certain industrial furnaces, the construction of parts which receive and convey molten slag to the quenching vessel is such that the mechanism or conveyance for transport of slag away from the furnace must be located at a considerable distance from the quenching station. This can be achieved by utilizing a relatively long chute and/or by placing the discharge end of the chute at a level well above the inlet, i.e., well above the quenching bath, and by employing one or more horizontal or slightly sloping belt conveyors, vibratory conveyors or scraper conveyors for further transport of slag which overflows the discharge end of the chute. Such mode of manipulating quenched slag is satisfactory as long as the slag need not be relieved of all, or a high percentage of, liquid which is entrained from the quenching vessel. The need for complete or practically complete segregation of quenched slag from liquid will arise when the slag must be loaded onto trucks or other types of vehicles in a cold climate or during the winter months because the liquid which drips from the trucks is likely to freeze on the road surface and renders the driving hazardous. Moreover, certain types of conveyors which are presently in use for transport of slag that overflows at the discharge end of an upwardly sloping chute are not entirely satisfactory. For example, a scraper conveyor is likely to undergo pronounced wear.